Based on lunar observations available in 1908, Poincaré established that h can be no greater than 10 m2/kg.

Christian wound the instrument daily, and checked it from time to time by means of lunar observations, taken with the help of Young.

He next studied all available lunar observations since the middle of the 17th century and reduced them to a uniform basis.

After all these improvements the tables provided an excellent fit to all lunar observations made since 1650.

Chapman was described as an expert navigator via lunar observations.

The invention of the optical telescope brought about the first leap in the quality of lunar observations.

However, much lunar observation was concerned with the phase of the Moon.

Its instruments performed lunar observations to within 25 minutes before impact.

The doctor took his bearings, by means of lunar observations, and consulted the excellent map that he had with him for his guidance.

He spent most of his time on lunar observations, but was also interested in the problems of gravity.